// This code is derived from jcifs smb client library <jcifs at samba dot org>
// Ported by J. Arturo <webmaster at komodosoft dot net>
//  
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
// 
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.
// 
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
namespace SharpCifs.Smb
{
    /// <summary>
    /// This class can be extended by applications that wish to trap authentication related exceptions and automatically retry the exceptional operation with different credentials.
    /// </summary>
    /// <remarks>
    /// This class can be extended by applications that wish to trap authentication related exceptions and automatically retry the exceptional operation with different credentials. Read <a href="../../../authhandler.html">jCIFS Exceptions and NtlmAuthenticator</a> for complete details.
    /// </remarks>
    public abstract class NtlmAuthenticator
    {
        private static NtlmAuthenticator _auth;

        private string _url;

        private SmbAuthException _sae;

        private void Reset()
        {
            _url = null;
            _sae = null;
        }

        /// <summary>Set the default <tt>NtlmAuthenticator</tt>.</summary>
        /// <remarks>
        /// Set the default <tt>NtlmAuthenticator</tt>. Once the default authenticator is set it cannot be changed. Calling this metho again will have no effect.
        /// </remarks>
        public static void SetDefault(NtlmAuthenticator a)
        {
            lock (typeof(NtlmAuthenticator))
            {
                if (_auth != null)
                {
                    return;
                }
                _auth = a;
            }
        }

        protected internal string GetRequestingUrl()
        {
            return _url;
        }

        protected internal SmbAuthException GetRequestingException()
        {
            return _sae;
        }

        /// <summary>
        /// Used internally by jCIFS when an <tt>SmbAuthException</tt> is trapped to retrieve new user credentials.
        /// </summary>
        /// <remarks>
        /// Used internally by jCIFS when an <tt>SmbAuthException</tt> is trapped to retrieve new user credentials.
        /// </remarks>
        public static NtlmPasswordAuthentication RequestNtlmPasswordAuthentication(string url,
                                                                                   SmbAuthException sae)
        {
            if (_auth == null)
            {
                return null;
            }
            lock (_auth)
            {
                _auth._url = url;
                _auth._sae = sae;
                return _auth.GetNtlmPasswordAuthentication();
            }
        }

        /// <summary>An application extending this class must provide an implementation for this method that returns new user credentials try try when accessing SMB resources described by the <tt>getRequestingURL</tt> and <tt>getRequestingException</tt> methods.
        /// </summary>
        /// <remarks>
        /// An application extending this class must provide an implementation for this method that returns new user credentials try try when accessing SMB resources described by the <tt>getRequestingURL</tt> and <tt>getRequestingException</tt> methods.
        /// If this method returns <tt>null</tt> the <tt>SmbAuthException</tt> that triggered the authenticator check will simply be rethrown. The default implementation returns <tt>null</tt>.
        /// </remarks>
        protected internal virtual NtlmPasswordAuthentication GetNtlmPasswordAuthentication()
        {
            return null;
        }
    }
}
